1. Field of the Invention
The present invention relates to a medical device. More specifically, it relates to devices for the treatment of dizziness.
2. Background of the Invention
Benign paroxysmal positional vertigo (BPPV) is the most frequent cause of peripheral vertigo. (Nedzelski J M, Barber H O, McIlmoyl L. Diagnoses in a dizziness unit. J Otolaryngol 1986 April;15(2):101-4). It is a disease of the balance organ in the inner ear which results in short lived but frequent episodes of spinning dizziness called vertigo. Though it typically resolves over several months without any treatment, a physician guided particle repositioning maneuver can expedite the process. The two fundamental maneuver variations are based on the techniques of Semont and Epley2, 3 who initially described the treatment of BPPV. Unfortunately, following either treatment maneuver, the condition is highly recurrent.
The current understanding of posterior canal benign paroxysmal positional vertigo (PBPPV) is that it occurs when otoconia, which are normal calcium crystals in the ear, become dislodged from the macula of the utricle, which is a part of the balance organ, and find their way into the ampullated end of the posterior semi-circular canal, which is a highly sensitive area for dizziness. Short lived rotational eye movements causing disorientation and associated vertigo results from the gravity induced movement of these calcium particles as they bump into the sensitive walls of the semicircular canals. While the duration of the disease itself is limited, the associated morbidity is high due to falls, depression, anxiety, injury and occupational hazard. Other forms of BPPV can occur when otoconia find their way into the superior and lateral canals which provide balance in the vertical and horizontal planes. These forms of BPPV are far less common and have a less symptomatic course.
The incidence of BPPV increases with age and has been estimated at greater than 10%-20% beyond the 6th decade of life. Reported recurrence rates vary widely and are dependant upon the duration of follow up. However, recurrence has been reported in as many as 30-50% of patients who undergo treatment by repositioning.
In the 1980s a series of exercises were developed which lead to a more rapid resolution of symptoms, these exercises were not therapeutic but rather caused the patient to become accustomed to the symptoms. However, these exercises required the regular induction of vertigo. After the description of new repositioning maneuvers by Semont in 1988 and Epley in 1992, effective treatments for the majority of patients became available. (Semont A, Freyss G, Vitte E. Curing the BPPV with a liberatory maneuver. Adv Otorhinolaryngol 1988;42:290-3) (Epley J M. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992September;107(3):399-404). Beyond particle repositioning maneuvers, there is no presently known effective non-surgical treatment for BPPV. Both singular neurectomy and posterior semi-circular canal occlusion are highly effective surgical procedures, but require a general anesthetic and the associated surgical morbidity.
There is a need for patients, community physicians and allied healthcare workers to be able to reproducibly perform particle repositioning maneuvers. Generally such maneuvers, while easy to perform, are somewhat difficult for patients to remember correctly. Incorrectly performed particle repositioning maneuvers are unlikely to be therapeutic.
There have been devices designed to assist in the performance of particle repositioning maneuvers. However, several difficulties exist with the design and use of these devices. These problems demonstrate the need for other devices to treat dizziness, and in particular an easy to use device which does not necessarily require a skilled individual for its operation.
There is a device for sale by Medical Surgical Innovations 1 Ocean Drive, Jupiter, Fla. which consists of a headband and skull vibrator. An adjustable neoprene headband is worn around the forehead. Attached to the headband at each temple in a plane parallel to the posterior semicircular canal is a circular channel filled with sand. The channel is designed to give feedback about the status of the patient's semicircular canals to a physician who is guiding a patient through the particle repositioning maneuver for PBPPV. As the physician guides the patient the physician can watch the particles in the channel move. This device is intended to be used by medical personnel and does not provide feedback directly to the patient. An associated vibrator is intended to be held against the skull to encourage the loose particles to move through the semicircular canal. The vibrator is a battery operated unit which is designed to be pressed against the skull and transmit kinetic vibratory energy into the skull.
U.S. Pat. Nos. 6,568,396 and 6,758,218 issued to P. Anthony describe devices using goggles. Generally speaking they consist of a set of large head worn goggles in which there is a fluid suspended, buoyancy neutral, inner spherical member upon which there is printed a sequence of numbers connected by a path. The inner member responds to gravity and magnetism and is contained within a watertight container with a sighting target printed upon it. The housing is held at a fixed distance close to the eye by a set of goggles which also contain a lens which is necessary to allow the patients wearing the device to focus upon the inner member. The user moves their head such that the outer housing moves with respect to the inner member. By aligning the sighting mark with the numbers printed on the inner member of the device the patient can follow the path traced out and complete a particle repositioning maneuver. Several inner members exist to diagnosis and treat various types of BPPV. A new inner member is required for each task related to BPPV and its diagnosis. The large, bulky and expensive outer housing is required to contain the inner member and the lenses required for viewing. These devices are complex and relatively difficult to use as there are a number of parts to exchange and align. In addition, these devices are not useful for providing feedback to medical or assisting personnel.
U.S. Pat. No. 6,029,670 describes a helmet with flat sides to assist in positioning a patient correctly. This device is only useful for one skilled in the particle repositioning maneuver. The device's intention is to ensure consistency between patient maneuvers. It is not a diagnostic device, nor does it provide visual feedback to either the user or physician.
A device described by Epley and Lempert consisting of a mechanical rotating chair has been used in some institutional settings. The rotational chair is akin to an amusement park ride wherein the rider is spun in 3 axes. The chair is connected to a computer into which can be input the exact nature of the semicircular canals. With this information the computer can calculate a path which will guide any loose otoconia out of the offending areas. By hydraulic and mechanical means controlled by the computer the chair is moved through this pre-calculated pathway. There exist only a very few of these devices worldwide as they are very large and expensive. They are typically used in tertiary care hospitals with a special interest in vestibular disorders.